However, the defensive end/linebacker says his health is not one of those issues. An NFL Network report had said McClellin had three concussions while playing at Boise State.
"It did bother me a little bit," McClellin said Friday. "I don't know where the reports came from. I had one concussion in 2010. I didn't miss a game. I missed one practice; they kept me out. In 2009, it wasn't really a concussion. I had concussion-like symptoms, but I was sick before that. It was more precautionary, and it wasn't really a concussion."
In essence, McClellin said he had only one actual concussion.
"I changed my helmet up this last year and I haven't had a problem since," he said. "So I'm good to go; no worries for me."
McClellin knows he'll have to live up to the faith the Bears put in him by selecting him over other better-known top defensive ends such as national sacks leader Whitney Mercilus of Illinois and Syracuse's Chandler Jones.
"To all the doubters, I'm going to have to go out there and prove myself," McClellin said Friday when he came to Halas Hall for the first time. "I'm used to that. I came from Boise State. We had to prove ourselves every week."
With 20.5 sacks and 33 tackles for loss through his four-year Boise State career, McClellin had good numbers. However, the fact he played at Boise State as opposed to a larger school was just one factor keeping his draft stock from going higher.
A perceived lack of great size, at 6-foot-3, 260 pounds, and the fact he was considered a 3-4 linebacker by some teams rather than an end in the 4-3 defensive style the Bears play also led to questions about why Chicago would want him at No. 19.
"It definitely puts a chip on my shoulder," McClellin said.
Copyright 2012 by The Associated Press